AutoHotkey Community

The ability to use DllCall within a function...

In the body of a function? In a function call (expression)? I think both of these work, so perhaps you could give an example.

Maybe it's the help file being vague again.

This seems to work ok:


This doesn't (unless it's something that I'm misunderstanding). It dies asking if I'd like to send a report to M$.


Edit: Spelling typos

Seems to be this line when within a function:

Splitting the line into 2 lines (2 separate calls) still seems to fail...
but... if either of these 2 lines are commented out the script does not crash (it doesn't work but doesn't crash).

I'm using AHK ver 1.0.33.01 & WinXP Pro SP2 btw

It took me a while to figure this one out because at first I was sure it was either a bug or something to do with your DLL's use of global memory (in spite of the fact that it copies its global memory to a safe area via lstrcpy before doing FreeLibrary).

But I think the solution is that you didn't give StrOut enough capacity. Try increasing it from 1000 to 5000. If it doesn't crash, use StringLen on the result. Chances are, it's bigger than 1000 (at least it is on mine).

Assuming this solves it, you might ask why it crashes only when called inside a function. It's probably because local variables use a different memory strategy than global variables -- one that might be more vulnerable to misdeeds such as buffer overflow.

By the way, if you have the DLL copy its result into a string provided by the caller, you can avoid the need for LoadLibrary(), FreeLibrary() and lstrcpy(). But from what you said before, perhaps there is a design reason you can't do this.

That would do the trick. Thanks.

I'll look into doing this. Thanks